Punch press control



Oct. 31, 1939. s. o. JOHNSON PUNCH PRESS CONTROL Filed April 1, 1938 INVENTOR.

' wfm 0. Moi/76017 A ORNlrYS Patented Oct. 31, 1939 UNITED STATES PATENT OFFiCE PUNCH PRESS CONTROL Gustav Johnson, Elkhart, Ind. Application April 1, 1938, Serial No. 199,471

11 Claims.

This invention relates to improvements in punch press controls.

The main objects of this invention are:

First, to provide a single-revolution control for a treadle operated or controlled punch press which is operative to stop the press after each revolution whether or not the operator releases the treadle.

Second, to provide a control of the type described which is simple in construction and capable of smooth and rapid operation.

Third, to provide a control of the type described which is unfailing in stopping the press after each reovlution, thereby preventing accidental injury or breakage of the die.

Fourth, to. provide a control of the type described embodying elements which are readily removable and quickly replaceable without stopping the machine if desired.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined in the claims.

A structure embodying the features of the invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a perspective view of a treadle operated press equipped with the control device of the invention, the flywheel being removed.

Fig. 2 is an enlarged fragmentary view in side.

elevation and partially in vertical section to illustrate details of the construction.

Fig. 3 is a fragmentary View in side elevation illustrating details of the construction in two operative positions thereof.

Fig. 4 is an enlarged fragmentary view partially broken away and in section to illustrate a further' detail of the invention.

Fig. 5 is an enlarged fragmentary view partially in section to more clearly illustrate the operation of the device.

The present invention relates to single-revolution control means for a treadle operated punch press which control means positively declutches the punch ram after each punching operation so as to prevent another cycle until the treadle has been allowed to return to raised position. Accordingly, if they operator neglects to take his foot off the treadle, the press ram will not descendagainv until the treadle is allowed to return to elevated position and is again manually actuated. To accomplish the foregoing operation, I employ a clutch latching assembly including a novel and improved toggle unit operatively associated with the usual clutchcontrolling shoe, the said toggle being broken, by actuation of the treadle to initiate a press stroke. To prevent a second stroke, I provide further means operatively connectedwith the toggle for straightening the same after any given downward press stroke has commenced, thereby again operatively positioning the shoe to disconnect the press from its flywheel and stop the ram at its uppermost point, as will be described. v

Referring to the drawing, the reference numeral I indicates an inclinable punch press of well known type, the operating elements of which are conventional and need no description here. The usual flywheel has been omitted for the sake of clarity, but the reference numeral 2 designates the square tool steel clutch pin usually employed for drivingly connecting the shaft 3 with the flywheel. The shoe 4 serves to control the engagement of the clutch pin 2 with the driving pins (not shown) in the flywheel in the usual manner. The details of this structure are well known and are therefore not further described. The shoe 4 is carried by an arm 5 pivotally mounted on the frame of the press at 6.

The present invention relates particularly to the structural details whereby the shoe 4 is actuated into engagement with the pin 2 to disconnect the same from driving relation with the flywheel, as follows: Arm 5, between shoe 4 and pivot point 6, is connected to one arm or link i of a toggle joint generally indicated 8, the other arm or link 9 thereof being pivoted at the fixed point H1 and, carrying an extension l I. The arms 1. and 9 are pivotally connected as by the movable pin l2.

The reference numeral l3 indicates an actuating link for the clutch control mechanism, which is operatively connected to the treadle Hi. This link has a notch l5 therein adjacent the toggle 8 and adapted to receive the pin l2. The link 13 extends upwardly between a pair of grooved guides or rollers 16 and is adapted to be swung or pivoted about these guides as a fulcrum so as to be capable of a definite lateral movement adjacent the toggle 8, as well as a lengthwise movement in the guides IE ,in a direction to break thetoggle. The stops I! are fixedly mounted on the press frame to limit the aforesaid lateral movement by engaging the link l3 when it is fully out of engagement with the pin l2. These stops may be integral portions of a housing l8 enclosing the toggle joint and associated elements. as illustrated in Fig. 1. Y

The link I3 is urged into opsition wherein the notch l5 receives the pin l2, i. e., to the left or counterclockwise as viewed in Figs. 1 and 2, by means of the thrust imparted by a pair of coil compression springs l9 interposed between a fixed abutment 20 on the press frame and an adjustable abutment 2| carried by the link. The mounting for these springs constitutes a portion of the present invention, and it therefore will be amplified hereinafter.

The function of link l3 is, in part, to break toggle 8 when actuated by the treadle. For this purpose it is evident that the link might, if detion at the top of its stroke sired, be operatively connected to the toggle or extension I l thereof at some other point than the middle pivot I2, as shown, and still effectively perform the same function.

Adjacent its upper end, the link I3 adjustably carries a follower 22 which is periodically engaged directly after the inauguration of each revolution of the shaft 3, i. e., after the beginning of each press stroke, by a cam 23 secured to rotate with the shaft. The follower 22 is adjustable lengthwise of the link in the track 24 at the upper end of the link, being secured in adjusted position thereon by the set screw 25.

A suitable counterbalancing weight 26 is mounted on the free end of the extension I l and serves to straighten the toggle joint 8 after the same has been broken by the link [3 and later released from the link as will be described. The arm 9 and extension H as well as arm 1 are pivoted for very free, floating movement under the influence of the link and weight.

My invention, as stated, includes a novel mounting for the thrust springs l9 whereby the same may be removed and replaced readily and quickly in case of breakage or for other reasons without necessarily stopping the flywheel. Referring to Fig. 4, it will be seen that the springs, are centered and held in position by pairs of pins 21, 28 on abutments and 2| respectively. The tubular sleeves 28 surround the springs l9 and are crimped inwardly at the bottoms thereof in order to enable the said springs tobe com pressed and removed from the pins 21, 28 by simply lifting the sleeves. In this manner, it is apparent that springs may be removed and replaced with a maximum of speed and a minimum of difficulty and without stopping the press. The abutment 2| is readily adjustable lengthwise of the link l3 by means of a clamping arm 30 and a set screw 3| carried thereby. It is therefore possible to regulate the thrust exerted by the springs l9 at will. Likewise, in the event it is desired to remove the link l3 entirely, this may be readily accomplished by loosening the set screws and 3| and sliding the link out lengthwise.

In operation, with the ram in operative posiand with the parts in position illustrated in solid lines in Fig. 2, the treadle is depressed. This lowers the link l3 and because of the engagement of the notch I5 thereof with the pin I2 the toggle joint 8 is broken, as illustrated in solid lines in Fig. 3, the shoe 4 is withdrawn outwardly, thus connecting the clutch pin 2 with the flywheel and starting rotation of the shaft 3. After the shaft has rotated a small portion of a revolution, the cam 23 engages the follower 22 and shifts the link 3 to the right as viewed in Figs. 2, 3, and 5, i. e., into the dotted line position of Fig. 3. This frees the pin l2 from its engagement by the notch l5 (see Fig. 5), and as soon as this occurs, the weight of the counterbalance 26 swings the extension ll downwardly to the dotted line position of Fig. 3 and straightens the toggle joint 8, thus pivoting the shoe arm 5 to the left as seen in Figs. 2 and 3 and returning the shoe 4 to operative position todisengage the clutch pin 2 from the flywheel when the shaft has completed a revolution. It will be perceived that whether or not the treadle M has been released by the operator, the driving connection for the press will be positively broken at the end of the stroke. The counterbalancing weight 25 is independent in its function of straightening the toggle of any springs or other parts, so that as long as the cam 23 strikes follower 22 each revolution, the press will be unfailingly halted each revolution. If it happens that the operator has not released the treadle, then the notch 15 will be in a position below the pin l2, but before this pin can again be engaged by the notch so as to break the toggle joint 8, the

treadle must be released and returned to original elevated position. This return is effected by the strong thrust springs I9.

I have illustrated and described my improvements in an embodiment which is very practical. I have not attempted to illustrate or describe other embodiments or adaptations as it is believed this disclosure will enable those skilled in the art to embody or adapt my improvements as may be desired.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In a single-revolution clutch control for a punch press, a shiftable clutch control member adapted to connect and disconnect the press from a driving instrumentality therefor, means for initiating operation of the press, said means including a toggle joint operatively connected to said member and to a fixed point on the press, a link mounted for lateral and longitudinal movement and having a portion engageable with said toggle joint, treadle actuated means for shifting said portion longitudinally to break said toggle whereby to shift said member and initiate operation of the press, means operated in timed relation to the press for shifting said link laterally to disconnect the same from the toggle joint, comprising a cam rotatable in synchronism with the press and a follower carried by the link and periodically engaged by the cam, and gravity actuated means for straightening said toggle joint when disengaged by said portion whereby to return said member to original position to terminate operation of the press.

2. In a single-revolution clutch control for a punch press, a shiftable clutch control member adapted to connect and disconnect the press from a driving instrumentality therefor, means for initiating operation of the press, said means including a toggle joint operatively connected to said member and to a fixed point on the press, a link mounted for lateral and lngitudinal movement and having a portion engageable with said toggle joint, treadle actuated means for shifting said portion longitudinally to break said toggle whereby to shift said member and initiate operation of the press, means operated in timed relation to the press for shifting said link laterally to disconnect the same from the toggle joint, and means for straightening said toggle joint when disengaged by said portion whereby to return said member to original position to terminate operation of the press.

3. In a single-revolution clutch control for a punch press, a shoe adapted to control movement of a clutch element into clutching or unclutching position to connect and disconnect the press from a driving instrumentality therefor, toggle means for controlling movement of said shoe, a link mounted for lateral and longitudinal movement relative to the press and having a notched portion engageable with said toggle means, treadle actuated means for shifting said link longitudinally to break said toggle means whereby to actuate the shoe and initiate opera tion of the press, means for shifting said link laterally to disconnect the notched portion from the toggle means comprising a cam rotatable in synchronism with'the press and .a follower carried by the link and periodically engaged by the cam, and gravity actuated means for straightening said toggle joint when disengaged by said notched portion whereby to return said shoe to position to terminate operation of the press.

4. Control means for an intermittently operated press comprising a movable clutch control shoe adapted to engage and disengage the clutch of said press with a driving instrumentality therefor, means for urging said shoe to disengaging position comprising a toggle joint operatively connected to the shoe and gravity operated means for straightening said joint, and means engageable with said joint to break the same and shift the shoe to engaging position comprising a link, treadle means for actuating the link, and means driven in synchronism with. the press for periodically disconnecting the link from the joint to permit the same to be straightened by said gravity actuated means and returned to disengaging position.

5. Control means for an intermittently operated press comprising a member adapted to connect and disconnect said press with a driving instrumentality therefor, means for urging said member into disconnecting position comprising a toggle connected with the member and means for straightening the toggle, means engageable with said toggle to break the same and shift the member to connecting position comprising a link, treadle means for actuating the link, and means driven in synchronism with the press for periodi cally disengaging the link from the toggle to per-- mit the same to be straightened by said straightening means.

6. Control means for an intermittently operated press comprising a member adapted to con-- nect and disconnect said press with a driving instrumentality therefor, means for urging said member into disconnecting position comprising a toggle connected with the member and means for straightening said toggle, means engageable with said toggle to break the same and shift the memher to connecting position, and means driven in synchronism with the press for periodically disengaging the link from the toggle to permit the same to be straightened by said straightening means.

7. In a press of the type described, a member adapted to connect and disconnect the press with a driving instrumentality therefor, means urging said member into position to disconnect the press comprising a toggle joint pivotally connected at its ends to said member and a fixed point on the press frame, and means tending to straighten the joint, link means engageable with the intermediate pivot of said toggle joint to break the joint and withdraw the member from said disconnecting position thereby initiating a press stroke, treadle means for actuating said link, means for disengaging said link means from the toggle after the initiation of the press stroke comprising a cam movable in synchronism with the press and a follower for said cam on the link means, means for guiding the movement of said link means, and means for returning said link means to original position when the treadle means is released comprising abutments on the link means and the press frame, a spring engageable between said abutments, pins on said abutments for positioning and centering said spring, sleeves surrounding said spring and having provisions for removing said spring, and

means for adjusting the relative position of said abutments.

8. In a press of the type described, a clutch member adapted to connect and disconnect the press with a driving instrumentality therefor, means for shifting said member into and out of operative position comprising a toggle joint pivotally connected at its ends to said member and a fixed point on the press frame, link means engageable with the intermediate pivot of said toggle joint to break the joint and withdraw the member from said operative position, treadle means for actuating said link, and means for returning said link means to original position when the treadle means is released comprising a fixed abutment and an abutment carried by said link means, a spring engageable between said abutments, pins on abutments for positioning and centering said spring, sleeves surrounding said spring and having provision for engaging and removing the same, and means for adjusting the relative position of said abutments.

9. In a clutch control means, the combination with a rotatable member provided with a releasable clutch element and with a cam, of a pivoted clutch releasing member operatively associated with said clutch element for engagement therewith as the rotatable member is rotated, a toggle comprising a pair of pivotally connected members, one of said toggle members being provided with an arm having an adjustable weight thereon and the other being pivotally connected to said clutch releasing member, a reciprocable manually actuated member operatively associated with said toggle for breaking the same, and a spring return means for said manually actuated means, said reciprocating means being provided with a tappet coacting with said cam on said rotatable member.

10. In a clutch control means, the combination with a rotatable member provided with a releasable clutch element and with a cam, of a pivoted clutch releasing member operatively associated with said clutch element for engagement therewith as the rotatable member is rotated, a toggle comprising a pair of pivotally connected members, one of said toggle members being provided with an arm having a weight thereon and the other being pivotally connected to said clutch releasing member, a reciprocable manually actuated member operatively associated with said toggle for breaking the same, and a spring return means for said manually actuated means, said reciprocating means being provided with a tappet coacting with said cam on said rotatable member.

11. In a clutch control means, the combination with a rotatable member provided with a releasable clutch element and with a cam, of a pivoted clutch releasing member operatively associated with said clutch element for engagement therewith as the rotatable member is rotated, a toggle comprising a pair of pivotally connected members, one of said toggle members being provided with an arm having a weight thereon and the other being pivotally connected to said clutch releasing member, a reciprocable manually actuated member operatively associated with said toggle for breaking the same, and a spring return means for said manually actuated means, said reciprocating means being provided with a tappet coacting with said cam on said rotatable member, said tappet being longitudinally adjustable on said manually actuated member.

GUSTAV O. JOHNSON. 

